Study: Men, women differ on recalling sexual histories

Ask any large group of men and women how many sexual partners they've had and, statistically speaking, the number should roughly be the same for both sexes. But, research shows, the number men come up with is two to four times larger than what women provide.

Are men lying to inflate their sexual reputations? Are women lying to downplay their sexual experience? Norman R. Brown, a psychologist and visiting research scientist at the U-M Institute for Social Research, believes this "macho and maiden" hypothesis is the wrong explanation. Men and women simply arrive at the number differently, he says.

"Women are more likely to rely on enumeration," said Brown. "They tend to say, 'I just know,' and if you ask them to explain how they know, they say, 'Well, there was John, Tom, etc.' This is a strategy that typically leads to underestimation. Men are twice as likely to use rough approximation to answer the question. And rough approximation is a strategy known to produce over-estimation."

Brown, a professor of psychology at the University of Alberta, and colleagues Robert Sinclair of Laurentian University and Sean Moore of the Augustana College, have conducted several studies of this issue. The largest and most recent is a Web-based survey conducted in fall 2005. The researchers polled a Knowledge Networks panel of 2,065 heterosexual, U.S. non-virgins with a median age in their late 40s. The average number of sexual partners the women reported was 8.6. The average number the men reported was 31.9. "The men in this survey were producing egregiously elevated responses," Brown said.

When asked a few minutes later how truthful their responses were, many research subjects, 21 percent of the men and 15 percent of the women admitted they had lied and/or they had provided an inaccurate partner count.

Sex Partner Estimation Strategy Menu

• I just now thought back over my lifetime and tried to remember and count each sexual partner.
• I made a rough guess, plus or minus a few sexual partners.
• It was a very small number, so I just knew.
• I keep a running tally of my number of sexual partners and I remembered this number (for example, I use a diary or I have been keeping track in my head over time).
• I thought about the number of different sexual partners who I've been with in an average year and multiplied by the number of years that I've been sexually active (for example, about 5 a year for 5 years equals 25).
• I used some other method to come up with my response.